The present disclosure relates to a sheet discharging device used in a copier, a printer, a facsimile machine, a multifunction peripheral serving as all of them, or the like, and also relates to an image forming apparatus provided with such a sheet discharging device.
An image forming apparatus is provided with a sheet discharge roller for discharging sheets (of a recording medium such as paper) having images formed on them by an image forming section. A sheet that has been transported from the upstream side of a discharge roller is delivered by the discharge roller onto a discharge tray. Inconveniently, when the sheet is delivered from the discharge roller onto the discharge tray, the trailing edge of the sheet tends to remain suspended on a lower roller constituting the discharge roller.
To overcome the inconvenience, according to one configuration, a projection is formed on the lower roller constituting the discharge roller so that the projection thrusts forth the trailing edge of a sheet toward the discharge tray. However, the projection protrudes, in the radial direction, from the circumferential face of the lower roller forming a nip portion. As a result, inconveniently, when the sheet passes through the nip portion of the discharge roller, the projection may damage the sheet, or may leave its mark on the image formed on the sheet.
Thus, there have been proposed methods for reliably thrusting forth a sheet from the discharge roller without damaging the sheet or the image on it. For example, in a known sheet discharging device provided with a discharge roller which discharges a sheet at a pressed-contact portion where a first and a second roller are in pressed contact with each other, there is provided a flick-out pulley arranged coaxially with the rotary shaft of the first roller at an interval from it so that the flick-out pulley, with a projection protruding in the radial direction from its circumferential face, flicks out the trailing edge of a sheet that is discharged as the first roller rotates, wherein the distance from the center of rotation of the flick-out pulley to the tip end of the projection in the roller radial direction is equal to or smaller than the radius of the cylindrical portion of the first roller.